Photovoltaic thermal (PV/T) system assisted heat pump utilization for milk pasteurization

Abstract

In this study, a hybrid photovoltaic-thermal heat pump system, supported by a four-pass economizer and a PV/T panel, has been installed to pasteurize milk to be processed into cheese. The surface temperature, which increases with the solar radiation value of the monocrystalline photovoltaic panel, has been decreased by transferring its heat to the water passing through the copper pipes that have been placed behind it. The study aims to try to increase the electricity generation by ensuring the cooling of the panel and while doing this, to make the thermal energy available for the pasteurization of milk, to meet some of the required energy from the PV/T system, to reduce the amount of energy consumed for pasteurization per unit of milk by shortening the pasteurization period, to increase system efficiency and focus on efficiency performances. The hybrid photovoltaic-thermal heat pump system has been compared with conventional methods. It has been determined that PV/T support and increasing raw (unpasteurized) milk flow from 120 l/h to 150 l/h have decreased the total pasteurization time and the thermal efficiency has increased by increasing the panel water flow. As a result of the experiments, it has been determined that the PV/T supported heat pump system has consumed approximately 73.3% less energy than the previously installed double-walled boiler system, 60.7% less than the plate pasteurizer system, and 25.5% less than the heat pump system. It has been determined that supporting the heat pump system established for pasteurization of milk with the PV/T system provides approximately a 8.8% reduction in the amount of energy consumed per kg milk.